As technology advances, the options for communications have become more varied. For example, in the last 30 years in the telecommunications industry, personal communications have evolved from a home having a single rotary dial telephone, to a home having multiple telephone, cable and/or fiber optic lines that accommodate both voice and data. Additionally cellular phones and Wi-Fi have added a mobile element to communications. Similarly, in the entertainment industry, 30 years ago there was only one format for television and this format was transmitted over the air and received via antennas located at a home. This has evolved into both different standards of picture quality such as, standard definition TV (SDTV), enhanced definition TV (EDTV) and high definition TV (HDTV), and more systems for delivery of these different television display formats such as cable and satellite. Additionally, services have grown to become overlapping between these two industries. As these systems continue to evolve in both industries, the service offerings will continue to merge and new services can be expected to be available for a consumer. Also these services will be based on the technical capability to process and output more information, for example as seen in the improvements in the picture quality of programs viewed on televisions, and therefore it is expected that service delivery requirements will continue to rely on more bandwidth being available throughout the network including the “last mile” to the end user.
Another related technology that impacts both the communications and entertainment industries is the Internet. The physical structure of the Internet, and associated communication streams, has also evolved to handle an increased flow of data. Servers have more memory than ever before, communications links exist that have a higher bandwidth than in the past, processors are faster and more capable and protocols exist to take advantage of these elements. As consumers' usage of the Internet grows, service companies have turned to the Internet (and other IP networks) as a mechanism for providing traditional services. These multimedia services can include Internet Protocol television (IPTV, referring to systems or services that deliver television programs over a network using IP data packets), video on demand (VOD), voice-over-IP (VoIP), and other web related services.
To accommodate the new and different ways in which IP networks are being used to provide various services, new network architectures are being developed and standardized. One such development is the Internet Protocol Multimedia Subsytem (IMS). IMS is an architectural framework which uses a plurality of Internet Protocols (IP) for delivering IP multimedia services to an end user. A goal of IMS is to assist in the delivery of these services to an end user by having a horizontal control layer which separates the service layer and the access layer.
In an IMS/IPTV environment, it is often desirable for a remote access function to be provided, e.g. to allow remote access to content that can be sent to the OITF or another terminal. Those skilled in the art will appreciate that remote access specifications are detailed in the ETSI TS 185 010 V 2.1.1 standard, which is publicly available. A mobile device, such as a mobile phone equipped with a remote access client, can access content in the home based on Digital Living Network Alliance (DLNA) and Universal Plug and Play (UPnP) procedures. This remote access requires the establishment of an IMS channel between the mobile and the gateway with a specific QoS. Once that IMS channel is established, Internet Protocol Security (IPSEC) is established between the remote ends to secure the traffic over that channel.
The IMS secure channel, once established, can be used to exchange DLNA traffic between the mobile and home devices in a secure manner. Once the mobile device selects specific content for streaming there are two options for allocating resources to stream the content. In a first option, the current QoS reservation for the already established IMS channel can be modified to allow for the additional bandwidth for the content to be streamed. A second option is to establish a second IMS channel with the proper QoS reservation, this second IMS channel is then used for streaming the content selected by the end user to be remotely accessed.
The aforementioned ETSI TS 185 010 V 2.1.1 standard specifies and describes the use of the first option. However, those skilled in the art will appreciate that this mechanism results in the content streamed to the mobile device being encrypted twice, which is inefficient, and increases the computational complexity of the decoding operation, which may be beyond the processing power available in many mobile devices. Additionally, the double decryption increases the latency, which has an adverse effect on the user experience.
As such the second option is more desirable. However, one issue related to the second approach is that for two IMS channels established between the mobile and the IMS gateway (IG) in the user premises, the IP address associated with each channel will be the same, although the ports are different. For the terminating side of the communication link (i.e., the IG side) the session border gateway (SBG) and/or edge router involved in IMS for reserving QoS often work at both the at the IP level and the port level.
On the other hand in the access network by which the mobile device is connected, typically a cellular data network, the GGSN only works at the IP address level. As such, the GGSN does not see any difference between the two IMS channels allocated to the same IG (which have the same terminating IP address but specify different ports), and from the GGSN point of view they are treated as a single QoS reservation. If normal IMS channel establishment procedures are followed, multiple QoS reservations will be made, one for the IMS channel used for DLNA control, and one reservation for the second IMS channel used for DLNA media streaming. For the second channel used for streaming, the GGSN will often return an error case, as the request to the GGSN for a new reservation will have the same IP addresses as the first channel for which the GGSN has already allocated a QoS when the first IMS session was established.
Therefore, it would be desirable to provide a system and method for providing remote access channels with accurate and valid QoS in a manner that, for example, prevents mishandling at intermediate nodes in the network.